Lead writer and executive producer, Steven Moffat, added: "I've known Michelle for years, and I'm thrilled to welcome her to 'Doctor Who.' She's everything we need – brilliant, Scottish, and a tiny bit satanic."

Filming is well underway for Series 8 of "Doctor Who." Guest stars confirmed to join Peter Capaldi and Jenna Coleman in the new series include Frank Skinner, Ben Miller, Tom Riley, Keeley Hawes and Hermione Norris.

You can check out photos of the Gatekeeper and the returning Cybermen below.